Skeletal Editing\nof Energetic Materials: Acid-Catalyzed\nOne-Step Synthesis of Bridged Triazoles as High-Energy-Density Materials\nvia the Nef Reaction

Thermally stable insensitive energetic materials have\ncaptivated\nsignificant attention from the global research community due to their\npotential impact. In this study, a series of symmetric and asymmetric\nnitromethyl-bridged triazole compounds were synthesized from pyrimidine\nmoieties via a skeletal editing approach. Additionally, carbonyl-bridged\ncompounds were synthesized in a single step by using acid-catalyzed\nNef reactions from their nitromethyl precursors. Peripheral modifications\nof pyrimidine resulted in fused energetic moieties. All synthesized\ncompounds were fully characterized by using infrared spectroscopy,\nhigh-resolution mass spectrometry, multinuclear magnetic resonance\nspectroscopy, elemental analysis, and differential scanning calorimetry.\nSingle-crystal X-ray diffraction analysis confirmed the structures\nof compounds <b>4</b> and <b>10</b>. The newly synthesized\nmoieties exhibit densities ranging from 1.75 to 1.86 g cm<sup>–3</sup>, detonation velocities between 8044 and 8608 m s<sup>–1</sup>, and detonation pressures between 23.10 and 30.31 GPa. Notably,\ncompounds <b>9</b> and <b>10</b> demonstrate exceptional\nheat resistance, with decomposition temperatures of 315 and 335 °C,\nrespectively. Computational studies, including density functional\ntheory, quantum theory of atoms in molecules, noncovalent interactions,\nand electrostatic surface potential analysis, account for hydrogen-bonding\nand noncovalent interactions. This work highlights the potential of\nskeletal editing in the development of high-performing, thermally\nstable energetic materials.